<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>VUE Template</title>
    <script type="text/javascript" src="../js/vue.js"></script>
</head>
<body>
    <div id="root">
        <h1>{{msg}}</h1>
    </div>
</body>
    <script type="text/javascript">
        //不要在选项 property 或回调上使用箭头函数，
        //比如 created: () => console.log(this.a) 或 vm.$watch('a', newValue => this.myMethod())。
        //因为箭头函数并没有 this，this 会作为变量一直向上级词法作用域查找，直至找到为止，
        //经常导致 Uncaught TypeError: Cannot read property of undefined 或 Uncaught TypeError: this.myMethod is not a function 之类的错误。
        const vm = new Vue({
            el:'#root',
            data:{
                msg:"hi, vue1"
            },
            beforeCreate() {
                console.log("beforeCreate");
            },
            created() {
                console.log('created,a is: ' + this.msg)
            },
            beforeMount() {
                console.log("beforeMount");
            },
            mounted() {
                console.log("mounted");
            },
            beforeUpdate() {
                console.log("beforeUpdate");
            },
            updated() {
                console.log("updated");
            },
        })

        setTimeout(() => {
            vm.msg = 'change...'
        }, 3000);
    </script>
</html>